Micro-computed tomography (µCT) is a non-destructive X-ray imaging method used in plant physiology to visualize in-situ plant tissues that enables assessments of embolized xylem vessels. Whereas evidence for X-ray-induced cellular damage has been reported, the impact on plant physiological processes such as carbon (C) uptake, transport, and use are unknown. Yet, these damages could be particularly relevant for studies that track embolism and C fluxes over time. We examined the physiological consequences of µCT-scanning for xylem embolism over three months by monitoring net photosynthesis (Anet), diameter growth, chlorophyll concentration (Chl), and foliar non-structural carbohydrate (NSC) content in four deciduous tree species: hedge maple (Acer campestre), ash (Fraxinus excelsior), European hornbeam (Carpinus betulus), and sessile oak (Quercus petraea). C transport from the canopy to the roots was also assessed through 13C labelling. Our results show that monthly X-ray application did not impact foliar Anet, Chl, NSC content, and C transport. Although X-ray effects did not vary between species, the most pronounced impact was observed in sessile oak, marked by stopped growth and stem deformations around the irradiated area. The absence of adverse impacts on plant physiology for all the tested treatments indicates that laboratory-based µCT systems can be used with different beam energy levels and doses without threatening the integrity of plant physiology within the range of tested parameters. However, the impacts of repetitive µCT on the stem radial growth at the irradiated zone leading to deformations in sessile oak might have lasting implications for studies tracking plant embolism in the longer-term.

中文翻译：

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体内 X 射线显微断层扫描局部影响茎径向生长，但没有立即的生理影响


微计算机断层扫描 (μCT) 是一种用于植物生理学的非破坏性 X 射线成像方法，可对原位植物组织进行可视化，从而能够评估栓塞的木质部血管。尽管 X 射线引起细胞损伤的证据已有报道，但其对碳 (C) 吸收、运输和使用等植物生理过程的影响尚不清楚。然而，这些损害可能与追踪栓塞和碳通量随时间变化的研究特别相关。我们通过监测四种落叶树种的净光合作用 (Anet)、直径生长、叶绿素浓度 (Chl) 和叶非结构碳水化合物 (NSC) 含量，检查了三个月内 µCT 扫描对木质部栓塞的生理影响：树篱枫树(Acer Campestre)、白蜡树 (Fraxinus excelsior)、欧洲角树 (Carpinus betulus) 和无梗橡树 (Quercus petraea)。还通过 13C 标记评估了从冠层到根部的 C 运输。我们的结果表明，每月 X 射线施用不会影响叶面 Anet、Chl、NSC 含量和 C 运输。尽管 X 射线效应在物种之间没有差异，但在无柄橡树中观察到最明显的影响，其特点是受辐射区域周围生长停止和茎变形。所有测试处理均未对植物生理学产生不利影响，这表明基于实验室的 µCT 系统可以使用不同的光束能量水平和剂量，而不会在测试参数范围内威胁植物生理学的完整性。然而，重复 µCT 对辐照区茎径向生长的影响导致无梗橡树变形，这可能对长期跟踪植物栓塞的研究产生持久影响。